Chassis for footwear and method of making footwear

ABSTRACT

An article of footwear comprises a chassis having an upper side and a lower side. At least one outsole component is attached to the lower side of the chassis, at least one midsole component is attached to the upper side of the chassis, and an upper is attached to the chassis. At least one opening extends through the chassis from the upper side to the lower side which is unobstructed by the outsole and midsole components. The openings allow for air circulation and water drainage. The chassis is comprised of multiple sub-frames that can be independently fastened to the other footwear components.

CROSS-REFERENCE

This application claims priority from co-pending U.S. provisional patent application Ser. Nos. 60/791,679 filed Apr. 12, 2006 and 60/812,287 filed Jun. 9, 2006, which applications are incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates generally to footwear, and particularly to a framework support structure or chassis for footwear.

BACKGROUND OF THE INVENTION

Conventional footwear includes a sole and an upper that is sewn, tacked, cemented or otherwise attached to the sole. Conventional shoe soles comprise one or more generally flat, planar layers of leather, rubber or synthetic materials, e.g., ethyl vinyl acetate. Sole structures for active footwear typically comprise multiple sole layers, including an outsole having traction and wear properties, a midsole having energy absorption properties, and an insole or sockliner for providing cushioning for the wearer's foot.

SUMMARY OF THE INVENTION

An article of footwear comprises a chassis having an upper side and a lower side. At least one opening and preferably multiple openings are defined in the chassis. The chassis forms a structural framework for the article of footwear. At least one and preferably multiple discrete outsole components are attached to the lower side of the chassis. Openings or gaps are provided in the outsole components or between outsole components. At least one midsole component is provided for cushioning, and is attached to the upper side of the chassis. Openings, gaps or spaces are provided within and between the midsole components. The gaps or openings in the chassis, outsole and midsole components are at least partially aligned with one another to provide a fluid flow path for air circulation and water drainage. At least one upper component, for example sandal straps, is attached to the chassis. A toe guard may also be attached to the chassis and extends up and over at least a portion of the toes of the user.

A method of manufacturing the article of footwear comprises forming the chassis of multiple sub-frame members, including a main sub-frame and a plurality of minor sub-frames. The midsole component(s) are attached to an upper side of the main sub-frame. The upper components are attached to the minor sub-frames in an operation separate from the step of attaching the midsole components to the main sub-frame. Next, the minor sub-frames are mechanically and adhesively joined to the main sub-frame. Finally, the outsole component(s) are attached to a lower side of the main sub-frame.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top, front perspective view of an article of footwear of the present invention;

FIG. 2 is a top, front perspective view of a chassis frame of the article of footwear of FIG. 1;

FIG. 3 is a bottom, front perspective view of the chassis of FIG. 2;

FIG. 4 is an exploded assembly view of a sole assembly of the article of footwear of FIG. 1;

FIG. 5 is a bottom view of the article of footwear;

FIG. 6 is a cross-section view taken along line 6-6 of FIG. 5; and

FIG. 7 is a cross-section view taken along line 7-7 of FIG. 5.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In contrast to conventional footwear having one or more generally flat, planar layers, the present disclosure provides a structural framework, i.e., a chassis, onto which selected components are attached. The framework is preferably three-dimensional, i.e., non-planar (not flat), and provides the structural support for other components of the footwear.

Turning now to FIGS. 1-3, one preferred embodiment of a chassis 10 for an article of footwear 22 is illustrated. Chassis 10 comprises a plurality of sub-frame structures 11, and numbered 13, 15, 17, 19, 21, which are joined together to form the support structure for the article of footwear 22. The chassis 10 is preferably three-dimensional, having (in a top plan view) an exterior outline generally corresponding to a human foot. Each sub-frame may be comprised of one or more frame members that are integrally molded together, or alternatively, separately formed and secured together to form the sub-frame. Because the chassis comprises sub-frames each of which is comprised of one or more frame members, each frame member can be designed, sized and located to provide desired structural and/or biomechanical functions.

The chassis 10 performs multiple functions in the article of footwear 22. Similar to an automobile chassis, chassis 10 is the structural framework upon which the footwear 22 is constructed. It lends structural integrity to the footwear 22. As will be described with respect to FIG. 4, the chassis 10 provides the structure upon which the other footwear components are mounted, including for example, outsole components, an upper, straps, arch support pads, cushions, toe guard and other footwear components. The chassis provides bio-mechanical properties such as a propulsive energy return, pronation and supination control, and otherwise stabilizes the foot during one's gait. Chassis 10 preferably has an open structure or otherwise comprises one or more openings which provide for fluid flow into and out of the foot receiving interior 22 of the footwear, thereby increasing airflow to the wearer's foot and allowing for drainage of water from the interior. The open structure also decreases the weight of the footwear. Although the preferred embodiment of the invention illustrated and described herein includes these features, other embodiments within the scope of the appended claims may have less than all features.

The chassis 10 includes a forefoot portion 14, a heel portion 16, a medial side 18 and a lateral side 20 corresponding to the forefoot, heel, medial and lateral sides of the wearer's foot. As best seen in FIG. 2, a main sub-frame 13 extends a majority of the length of the chassis 10, from the forefoot portion 14 to the heel portion 16. In the preferred embodiment, the main sub-frame 13 does not extend the full length of the article of footwear 22, but extends substantially into the forefoot and heel regions of the footwear. However, it is contemplated that the chassis 10 can extend the full length of the article of footwear 22.

Preferably, minor sub-frames 15 and 17 are located at the medial side 18 and the lateral side 20 of the forefoot portion 14, respectively, and minor sub-frames 19, 21 are located at the medial side and the lateral side of the heel portion 16, respectively. While the preferred embodiment has four minor sub-frames 15, 17, 19, 21 at the four specified locations, alternative numbers and arrangements of sub-frames are contemplated. The sub-frames 15, 17, 19, 21 are preferably adapted for attachment of straps that comprise the upper portion of the footwear, as described below.

Referring to FIGS. 5 and 6, the sub-frame structures 11 may include discrete frame members or ribs 12, which may be separately or integrally formed with the other portions of the sub-frame. Preferably, the main sub-frame 13 extends between the forefoot 14 and heel portions 16 of the footwear. The frame members or ribs 12 provide structural support to the sub-frame. Relatively thinner planar members 25 may extend between frame members 12. Further, the relatively thinner and more flexible planar members 25 preferably extend from the frame members 12 towards the forefoot portion 14 and the heel portions 16.

The main sub-frame 13 is preferably made of a strong, light-weight resilient material, such as thermoplastic urethane (TPU), however other materials can be used. A TPU material with a durometer of about 64 Shore D has been successfully used for the main sub-frame. The ribs 12 and the planar members 25 are preferably made of the same material having the same durometer, however it is contemplated that different materials can be used. Preferably, the main sub-frame 13 differs in flexibility from one area to another area to provide a specific structural and/or biomechanical function. In the preferred embodiment, stiffer ribs 12 are disposed at the arch, and thinner, more flexible planar members 25 are disposed at the forefoot 14 and heel portions 16. The ribs 12 provide arch support while the flexible planar members 25 allow flex at the forefoot 14 and heel portions 16.

The minor sub-frames 15, 17, 19, 21 are preferably formed from the same material as the main sub-frame. However, in some applications, it may be preferable to fabricate the minor sub-frames 15, 17, 19, 21 from different materials (or the same material of different hardness) to provide selected strength, resilience, flexibility and other properties. Additionally, the individual sub-frames 11 and/or the combinations of frame structures may provide specific biomechanical functions. For example, the forefoot portion 14 of the sub-frames 11 may be provided with different biomechanical properties than the heel portion 16.

The sub-frames 11 are mechanically connected to each other with interlocking, snap-together puzzle-piece shaped connectors. The minor sub-frames 15, 17, 19, 21 have a connection portion 28 for connecting to the main sub-frame 13, and an extension portion 30 extending generally perpendicular to the main sub-frame. In addition, the sub-frames 11 are cemented to the main sub-frame. The puzzle-piece connectors provide a positive mechanical connection that resists pull-out. Although the cemented and mechanical connection is preferred, alternatively, sub-frames 11 can be connected to each other ways, including joints that permit relative movement of one sub-frame relative to another, such as flexible, hinged or pivotal connections. For example, the medial, forefoot sub-frame 15 could be pivotally connected so that it can pivot with respect to the main sub-frame 13.

Preferably one or more of the sub-frames 11 includes at least one opening 56 to permit fluid, including air and water, to flow through the footwear. More preferably, multiple openings 56 are located at the forefoot 14 and heel portions 16. The openings 56 are preferably covered with a mesh screen 29 to minimize the entry of unwanted debris into the interior of the footwear 22. Preferably, the mesh screen 29 is disposed on an upper side 31 of the chassis; however, other locations are contemplated. Further, it is contemplated that the mesh screen 29 can be located on an upper side 33 of the outsole components 24 or on the midsole components 36.

Turning now to FIG. 4, various footwear components are attached to the chassis 10. While particular footwear components will be described herein, it is contemplated that any number and arrangement of components can be incorporated with the chassis 10.

At least one and preferably multiple outsole components 24 are attached to a lower side 26 of the chassis 10. In the preferred embodiment, multiple outsole components 24 are attached to the lower side 26 of the chassis 10 in a spaced-apart relationship, preferably at the contact points of the footwear to the ground. FIG. 5 shows two discrete outsole components 24, namely forefoot and heel outsole components. The outsole components are positioned so that one or more of the chassis openings are unobstructed by the outsole components.

The sub-frames 11 preferably include at least one protrusion 37 on the lower side 26 of the chassis 10 (see FIG. 3). The protrusions 37 are received in openings 39 in the outsole components 24 so as to locate and properly align the outsole components on the chassis. It is contemplated that the protrusions 37 can be located on any of the sub-frames 11, and on more than one sub-frame. The outsole components 24 are preferably cemented to the chassis with adhesive.

As seen in FIGS. 3 and 5, lugs 41 project from the exterior surface of the chassis 10, preferably from the main sub-frame 13. The lugs 41 preferably span the channels and are configured to extend through the channels in the outsole components 24. The lugs 41 are preferably triangular in shape and function to properly locate and register the outsole components during assembly, and to minimize the entry of debris into the channel within or between outsole components 24 when the footwear is in use. Additionally, the lugs 41 stabilize and strengthen the forefoot portion 14 of the main sub-frame 13. Because the outsole components 24 are discrete components, each may be different materials and/or may have different properties, e.g., hardness, coefficient of friction, wear resistance, designed to maximize performance of each component. The outsole components 24 are not structural components inasmuch as they primarily function to provide traction and wear. Thus, the design and material options for the outsole 24 are more flexible since they are not required to provide structural integrity to the footwear.

The chassis 10 preferably comprises plural components for support, shock absorption and cushioning, which are referred to herein collectively as midsole components 36A, 36B. See FIG. 4. The midsole component 36A is cradled inside the chassis 10, and preferably is cemented to the upper side 31 of the chassis. The midsole component 36B is preferably cradled inside the midsole component 36A and has an upper side 38 which is preferably contoured to the foot. Preferably made of an elastomeric material, rubber or foam (such as ethyl vinyl acetate), the midsole components 36 are compressible and cushion the foot from impacts associated with movement. Alternatively, one of more midsole components 36 can comprise one or more bags filled with gel, gas, liquid, foam or a combination of materials. The midsole components 36A, 36B can be individually designed for specific performance criteria. Alternatively, a single midsole component 36 can be used.

Midsole components 36A, 36B preferably include ports 23 as shown in FIGS. 4 and 7. Preferably at least some of the midsole ports 23 are in alignment with openings 56 in the chassis 10 so that the midsole does not obstruct the chassis openings. Further, at least one but preferably several channels 60 are formed in the midsole components 36, or alternatively, between multiple midsole components. As seen in FIG. 7, at least one midsole port 23 is at least partially aligned with openings 35 in outsole components 24. With this construction, water can drain out of and air can circulate within the article of footwear 22. While the channels 60 and ports 23 are shown in a generally vertical orientation, it is contemplated that other alignments may be used as long as the channels and ports permit fluid flow.

Referring back to FIG. 1, upper components 40 are connected to the chassis 10. The upper may be enclosed as in a shoe or boot, or may be open as in a sandal. In the illustrated embodiment, the upper components 40 comprise a plurality of sandal straps 42. As seen in FIGS. 5 and 6, the main sub-frame includes a midfoot channel 27 for receiving an adjustable strap, as disclosed in commonly owned U.S. Pat. No. 6,606,803, which is incorporated herein by reference. Further, the sandal structure may have a strapping system such as that disclosed in commonly owned U.S. Pat. No. 4,793,075, which is also incorporated herein by reference.

The straps 42 are connected to the chassis 10, preferably at the minor sub-frames 15, 17, 19, 21. The straps 42 are sewn to the minor sub-frames 15, 17, 19, 21. The minor sub-frames 15, 17, 19, 21 preferably include an attachment portion 46, which is preferably an opening or an area having material properties that enable the straps 42 to be directly attached. In the preferred embodiment, the attachment portion 46 is recess for receiving an end portion of a strap. Alternative means for attaching the upper to the chassis can be used, in addition to or in lieu of stitching, including adhesives and rivets, for example.

The upper components 40 are preferrably attached to the sub-frame structures 15, 17, 19, 21 independently of the construction of the other footwear components to the main sub-frame 13. This allows greater flexibility in the manufacturing process. It also reduces the risk of damage to the upper components 40 during assembly. The midsole components 36 can be cemented to the main sub-frame 13, while in a separate operation, the upper components 40 can be attached to the sub-frames 15, 17, 19, 21. Because these operations are separate, the upper components 40 are not exposed to the cement used to secure the midsole components 36 and thus cannot be damaged by the same.

The upper further preferably includes a liner 43. The liner provides cushioning between the sandal straps and the foot. Although the liner may be made in multiple pieces, it is preferably a single sock. The liner may comprise a composite foam and nylon fabric or other relatively material. The liner is attached at multiple locations to other upper components and/or the midsole by sewing and/or adhesive. The liner may, but need not register with the straps 42.

Another optional upper component incorporated on the article of footwear 22 is a toe guard 44. Having a generally cupped-shape, the toe guard 44 extends up over the top of the user's toes. The toe guard 44 is disposed at the medial side 18, preferably to cover at least a portion of at least the first digit. The toe guard 44 preferably extends to the upper 40. Preferably the toe guard is formed separately from the other footwear components. It is attached to the chassis by any conventional means, e.g., by adhesive. The toe guard can be independent of the other upper components, however the liner or a portion thereof is preferable secured to the inner surface of the toe guard.

Other components can be incorporated on the chassis 10, such as a shank, or a shock pad. Additionally, the chassis 10 may have sub-frames 11 that run the entire length of the article of footwear 22, may extend across selected portions of the footwear. Preferably, when the chassis 10 is assembled in the article of footwear 22, the chassis 10 is exposed from both the inside of the upper 40 and the outside of the footwear.

While the preferred embodiments of the present invention have been shown and described, it is to be understood that these are merely examples for practicing the invention that the inventor foresees at the present time, and that various modifications and changes could be made thereto. In particular, various other chassis assemblies could be designed by persons skilled in the art. 

1. An article of footwear comprising: a non-planar chassis having an upper side and a lower side; at least one outsole component attached to said lower side of said chassis; at least one midsole component attached to said upper side of said chassis; and an upper attached to said chassis and defining a foot receiving space; at least one opening extending through said chassis from said upper side to said lower side and being unobstructed by said outsole component and said midsole component, said opening adapted to permit fluid flow into or out of said foot receiving space.
 2. The article of footwear of claim 1 further comprising at least two said outsole components.
 3. The article of footwear of claim 2 wherein said upper is sewn to said chassis.
 4. The article of footwear of claim 1 wherein said upper comprises at least one strap and said chassis has a midfoot channel disposed generally transversely through said chassis for slidably receiving said strap.
 5. The article of footwear of claim 1 wherein said chassis has a screen disposed over said opening.
 6. The article of footwear of claim 1 wherein said midsole component has at least one midsole port extending through said midsole from an upper side thereof to a lower side thereof, wherein said midsole port is aligned with said chassis opening.
 7. The article of footwear of claim 1 wherein said chassis comprises a plurality of sub-frames that are attached to each other with a mechanical, interlocking connection.
 8. The article of footwear of claim 7 wherein said plurality of sub-frames comprise: a main sub-frame extending from a forefoot to a heel portion of the article of footwear; and at least two minor sub-frames, one said minor sub-frames being attached to the medial side of said main sub-frame, and another said minor sub-frame being attached to the lateral side of said main sub-frame, said upper being attached to said minor sub-frame portions.
 9. The article of footwear of claim 8 wherein there are at least four said minor sub-frames, two of said minor sub-frames being attached to the medial side of said main sub-frame, and another two of said minor sub-frames being attached to the lateral side of said main sub-frame, said upper comprising sandal straps that are attached to said minor sub-frames.
 10. A method of manufacturing an article of footwear comprising: forming a main sub-frame; forming a plurality of minor sub-frames, attaching at least one midsole component to an upper side of said main sub-frame; and attaching an upper to said minor sub-frames in an operation separate from the step of attaching said midsole component to said main sub-frame; connecting said minor sub-frames to said main sub-frame; and attaching at least one outsole component to a lower side of said main sub-frame.
 11. The method of claim 10 further comprising forming at least one opening in said main sub-frame, said opening extending through said main sub-frame from the upper side to the lower side thereof.
 12. The method of claim 10 wherein the step of connecting the minor sub-frames to the main sub-frame comprises joining said sub-frames with a mechanical, interlocking connection.
 13. The method of claim 10 wherein said plural minor sub-frames include an extension portion extending generally perpendicular to said main sub-frame.
 14. The method of claim 13 wherein said step of attaching said upper to said minor sub-frames comprises sewing said upper to the extension portion of each of said minor sub-frames.
 15. A framework structure for an article of footwear having an upper, comprising: a main sub-frame extending substantially the forefoot region to the heel region of the footwear; a plurality of minor sub-frames mechanically connected to said main sub-frame to form a chassis, said sub-frames having portions adapted for connection to the upper.
 16. The framework structure of claim 15 wherein at least one minor sub-frame is attached to a medial side of said main sub-frame, and at least one other minor sub-frame is attached to a lateral side of said main sub-frame.
 17. The framework structure of claim 15 wherein said chassis comprises a lower side configured to receive one or more outsole components, and an upper side configured to receive one or more midsole components.
 18. The framework structure of claim 15 further comprising a midfoot channel disposed generally transversely through said main sub-frame, generally from a medial side to a lateral side, and configured for slidably receiving a strap.
 19. The framework structure of claim 15 further comprising at least one opening through said framework structure from an upper side to a lower side thereof.
 20. The framework structure of claim 19 further comprising a screen over said opening. 